MEDICAL PHYSIOLOGY

Detailed explanation-1: -A motor unit is made up of a motor neuron and all of the skeletal muscle fibers innervated by the neuron’s axon terminals, including the neuromuscular junctions between the neuron and the fibres. Groups of motor units often work together as a motor pool to coordinate the contractions of a single muscle.

Detailed explanation-2: -Remember that a muscle fiber is the same thing as a muscle cell. A single efferent neuron typically controls multiple muscle fibers, and there are many many neurons that control different muscle fibers in a single muscle. A single efferent neuron and all of the muscle fibers that it controls is called a motor unit.

Detailed explanation-3: -An alpha motor neuron and the muscle fibers it innervates is a motor unit.

Detailed explanation-4: -The synapse of a motor neuron with a muscle fiber is known as the neuromuscular junction, or NMJ. The function of the neuromuscular junction is to transmit a signal, called a nerve impulse (which is actually an action potential of the neuron), from the neuron to the sarcolemma of the muscle fiber.